PIMS-CSC Distinguished Speaker Series: Viscometry of bulk materials and atomic structures

Perhaps the most important deformations in solid mechanics are those that represent the bending, twisting and extension of beams. The most important flows in fluid mechanics are viscometric flows. In both cases these are the motions that, when compared with the corresponding experiments, are used to measure the material constants. We give a universal molecular level interpretation of these motions. We argue that all these motions are associated at molecular level with a time-dependent invariant manifold of the equations of molecular dynamics. The presence of this manifold can be used to simplify molecular-level computations, and deliver viscometric properties in the absence of a constitutive relation. Interesting links to theories of turbulence, to the kinetic theory of gases (i.e., the Boltzmann equation), to the dynamics of nanostructures, and to the Langevin equation will be briefly discussed. Joint work with Kaushik Dayal, Traian Dumitrica and Stefan Mueller.